In the course of the recent years, the scope of utilizing UAV's grew and expanded noticeably, particularly for military tasks. As a rule, the constraints imposed on UAV's usage stems from the requirement of employing a rather long runway for their “take off's” (i.e., launching) and landings.
At the same time, a need for a new operational approach has developed, calling for long stay in the air of one or more UAV flying over a given geographical sector of interest, for example—in order to locate a target at that defined sector and guiding an armament toward the target. Other examples are such as—utilizing the UAV as a decoy or for a tactical reconnaissance mission.
This is an operational need, whose derivative is a requirement to launch UAV's at a high rate and safely retrieving them, in a manner enabling their recurring use. Moreover, the assimilation of UAV's services leads to the requirement that operating them would not only be possible from orderly, large area landing strips, as said, but also from over mobile platforms endowed with relatively small dimensions. For example, from the decks of missiles' boats, frigates and corvettes, wherein using the UAV is the equivalent of elevating their masts (tall mast substitute) provides surveillance beyond the horizon, so that a UAV launched over a vessel gives observation capability to a range of 50 to 100 miles.
In addition, urban arenas wherein armed conflicts are currently taking place, leads to the requirement that operating UAV's' would be available from a ground confined urban space and not just from an orderly, large area landing strips.
Diverse systems and methods were offered in the past in order to impart launching and landing capability of UAV's from mobile platforms, such as vessels, as stated above.
A U.S. Pat. No. 3,980,259—Aircraft Recovery Methods, describes a system for landing an RPV (remotely piloted vehicle) on a mobile platform (for example, a vessel) by using a hovering parachute that is spread over the airborne vehicle and a cable that is let down from the RPV and is subsequently tied to the platform; the cable serves to pull the RPV unto the platform (in a similar mode as retrieving a kite).
A “shipboard air vehicle retrieval apparatus” is described in U.S. Pat. No. 4,753,400. The device described in this patent is based on a parachute with lift force and a net parachute that is linked to it, and they both are connected to the vessel with a cable. The lift-up parachute stabilizes the net parachute wherein it is tied by the cable to the vessel. The unmanned vehicle is led to the net parachute and after its collision with the net parachute and being made to land there, the cable is pooled and rolled back into the vessel.
U.S. Pat. No. 4,790,497 describes a “point landing method for non vertical takeoff and landing flying objects”. This method is based on tying up—during the flight, a cable from the flying vehicle to an anchoring means, and subsequently pulling the vehicle in flight to the designated touchdown point—using a winch in the course of continuous flight of the vehicle.
U.S. Pat. No. 5,109,788 describes an “apparatus for recovery of an unmanned, reusable aircraft”. The subject matter of this patent is a trampoline-like device that is opened and spread unto the outside of the mobile platform (for example, the wall of a vessel) in order to land the aerial vehicle on the vessel.
U.S. Pat. No. 6,874,729 describes a “Launch and recovery system for unmanned aerial vehicle”. The system launches the aerial vehicle by hoisting it aloft using a hovering parachute, and dropping it from there—from the hovering parachute that is tied to the mobile platform (for example, a vessel). In a preferred configuration of the system that is described in the patent, the system even retrieves the aerial vehicle and lands it into a net that is spread aloft (at a pre-set height) using a system comprising a cable and the hovering parachute.
Patent application EP 1602576 describes an “Unmanned aerial vehicle deceleration system” that is based on damping the UAV landing through propelling of a braking device into which the UAV collides (for example, a net-like device), in the direction of the UAV's flight and from the force of the collision (of the UAV unto the net), until the UAV is stopped. The major part of the kinetic energy is absorbed during the process due to the aerodynamic drag that is generated by the mobile braking device.
All the above cited systems and methods do not impart a suitable solution to the challenge presented by the tactical requirement of high rate launching and landing of an UAV from and upon a mobile platform whose dimensions are relatively small (for example, a vessel) as stated, which is really the challenge presented by the cited operational requirements.
Verily, the launching of a UAV might be aided by a pyrotechnic device (such as an accelerating rocket) that exhausts and is cast off away from the UAV after its launching, but even more than the environmental danger generated by such a device and its relatively high costs, we are still left with the problem of retrieving the aerial vehicle.
Landing a UAV by tying the aerial vehicle to a cable that is dropped off from the UAV, sending aloft hovering parachutes from the platform or setting up net means on the platform, as were described in the above cited patents documents, do not yet provide an adequate solution. The implementation of solutions as presented mandates to employ operating teams endowed by high expertise and specialized capabilities, combined with an increase of the mobile platform's dimensional and “signature”—rendering to higher danger of being detected combined with the potential interference—up to shutting off—with the operation of arms and surveillance equipment on board the platform (due to the deployment of cables, parachutes and the like in close vicinity on board the platform).
Thus, at the period preceding this current invention, there existed the long felt and continuous need for a compact landing and launching UAV's system that would be distinguished by its small dimensions, installable on a relatively small mobile platform (for example, a missiles boat) while being integrated with the armament and detection systems aboard these platforms on the one hand but without causing interference to their battle operational modes and equipment, culminating in a launching and landing system that is easy to maintain and operate and that would impart UAV's launching and landing capability at a high rate and with remarkable reliability and safety features.